Ncert Exercises & Solutions

When two waves of almost equal frequencies $n_{1}$ and $n_{2}$ reach a point simultaneously, what is the time interval between successive maxima?

Hint: Use the concept of beats.

Step 1 : Find the beat frequency .

Let, n_{1} > n_{2}

Beat frequency, ν_{b} = n_{1} - n_{2}

Step 2 : Find the interval between successive maxima .

∴ Time period of beats = T_{b} = \frac{1}{ν_{b}} = \frac{1}{n_{1} - n_{2}}